This invention relates to a variable ignition distributor, more particularly to an improvement in an ignition distributor having a system of dual electrodes in a gasoline engine. Especially, this invention provides a variable ignition distributor which is capable of inhibiting the excessively rich mixture in the intake cylinder, reducing the delay time of flame propagation from the ignition electrode to the fuel and facilitating the complete combustion of the fuel, thereby saving the fuel and increasing the output of power of the gasoline engine. The invention provides a high-voltage spark to combust the fuel in the explosion cylinder and, by supplying and fine spark to the intake cylinder, ensures that optimum explosion environment can be formed in the intake cylinder. The invention further provides that the ionization of the fuel inhaled in the intake cylinder, as well as the compounding of the fuel with the air, can sufficiently be effected.
In most of the conventional distributors, the spark is directed to the air-fuel mixture compressed in the combustion chamber wherein explosion is effected, thereby output of power is produced, and, thereafter the fuel is inhaled again into the intake cylinder. At this time, the pistons are moved downward and the air which has passed through the air-cleaner will pass into the carburetor. The air from the carburetor is mixed with the fuel depending upon its flow speed and the air-fuel mixture is inhaled into the combustion chamber. The pressure of the air because of the downward moving of pistons is reduced to less than the atmospheric pressure. This phenomenon becomes severe with the increase of the rotation per minute of the engine and the flow rate of the air, which has passed through the carburetor, also becomes faster, thereby the fuel is poorly mixed with the air and is inhaled into each combustion chamber. Therefore, the explosion is effected by a spark, via the compression stroke, to the air-fuel mixture which is inhaled into the combustion chamber.